Fig. 9.Deformity in case of wound of ulnar nerve above wrist.
Fig. 9.Deformity in case of wound of ulnar nerve above wrist.
Fig. 9.
Deformity in case of wound of ulnar nerve above wrist.
The treatment is to seek for the divided ends of the nerve, and to unite them if possible. Should the interspace be too great to allow direct suture, an attempt might be made to restore continuity by cutting a long flap from the proximal extremity of the nerve and bringing it down to the distal end; or by the transplantation of a portion of nerve from an amputated limb, or from one of the lower animals. Where the wound lies immediately above the wrist, it is well to remember that the ulnar nerve and vessels are covered by a fibrous band, which passes from the radial side ofthe flexor carpi ulnaris tendon in this situation to blend with the anterior annular ligament. It should also be recollected that the deep branch of the nerve, which is occasionally implicated in penetrating wounds over the hypothenar eminence, runs around the ulnar side of the tip of the unciform process, and may there be exposed without much difficulty.[7]After operation the hand should be placed in a position of adduction and flexion, and the wound dressed antiseptically. Should this measure fail, the apparatus devised by Duchenne may be applied to replace the action of the paralysed muscles.
Musculo-spiral paralysismay be induced by ordinary wounds or contusions, by fractures of the humerus, or by long-continued compression of the nerve against the bone, either by the handle of a crutch, or while the patient is sleeping with his head resting upon an arm which is supported by the back of a chair. The consequences are paralysis of the elbow extensors, the supinator longus, the supinator brevis, and the whole of the extensors of the wrist, thumb, and fingers; and loss of sensation over the cutaneous areas supplied by the nerve in the arm, forearm, and hand. For the patient the most striking symptoms are the flexion of the wrist and fingers, the loss of power to abduct the thumb, and especially theenfeeblement of grasp due to the inability to fix the wrist during the action of the finger flexors. If the wrist be held firmly by the other hand, or by another person, in the position of extension, the power of grip becomes restored. A similar condition is present in lead poisoning; but here the loss of power is confined to the extensor muscles, and the supinator longus remains unaffected. The possibility of a crutch paralysis should lead the surgeon to warn every patient who is compelled to use the implement, in order that the paralysis may be prevented, or, should it occur, that it may be perceived and arrested in its earliest stages. When the condition has become established, an attempt should be made to restore function by massage and electricity, and if these fail, the nerve should be exposed at the seat of injury, and its continuity restored by the excision of the atrophic portion and union of the two free extremities.
In paralysis of theMedian nerveby a wound above the wrist, the most distressing symptoms are referable to the trophic lesions in the integuments of the thumb, index, middle, and ring fingers (radial side) on their palmar surface and the distal half of their dorsal aspect. There is, in addition, a partial loss of power of flexion and abduction of the thumb, with wasting of the thenar eminence and some interference with the delicacy of the movements of the index and middlefingers, owing to the paralysis of the first and second lumbricales. If the nerve be divided above the elbow, the pronators and all the flexors of the wrist, thumb, and fingers, except those supplied by the ulnar nerve (flexor carpi ulnaris, and ulnar half of the flexor digitorum profundus), are paralysed, and consequently the hand is, for all practical purposes, quite useless. The rules for treatment are similar in principle to those laid down for injuries of the musculo-spiral and ulnar nerves.
Spastic Paralyses, in connection with central disease, need not be discussed; but the surgeon is sometimes consulted for conditions of persistent spasm which apparently depend upon excessive use of certain muscles. Erichsen refers to, and figures, a case of flexion with pronation attributed to cutting with heavy shears. He notes that when the wrist was extended the fingers became flexed, and when the wrist was extended the fingers became bent in. It is not stated whether the permanency of the contraction was tested by the use of an anæsthetic, but the patient, as well as another in whom the extensors were affected in like manner, became cured by means of friction and galvanism, with the use of a straight splint. A case of spastic contraction of the right little finger of thirty-five years’ duration was recently in the Mile End Infirmary. The flexion of the finger is associated with slight adduction of the hand, but the parts can be straightened completelyby passive force. The condition is attributed to a wound near the elbow. There is no lesion of sensation.
The group of affections known asWriter’s crampusually fall within the province of the physician, and will only be briefly referred to. They are of uncertain pathology, vary considerably in their manifestations, and, although most common in persons much engaged in writing, are by no means confined to these. The symptoms may assume three different types—spastic, paralytic, and tremulous—affecting the muscles of the hands and forearm, and these may be combined in various ways. The prognosis is unfavourable; but the treatment found most hopeful is to relieve the affected muscles from the strain to which they have been accustomed, and strengthen them by massage and galvanism. Interference by surgical operation has been unsuccessful, except in one case, in which Stromeyer divided the flexor longus pollicis tendon.
These are usually of paralytic origin, but include a proportion of cases of true hammer finger. The common form is that already described by Mr. William Adams (Medical Society, December 1890), in which the inter-phalangeal joints of one or more fingers (most frequently the fifth) are flexed, andthe integument on the palmar aspect forms a longitudinal fold, which becomes tense when an attempt is made to straighten the digit; the metacarpo-phalangeal joint is super-extended. At first the finger may be fully extended by passive force, but after a few years the position of flexion at the first inter-phalangeal joint is rendered permanent by imperfect development of the ligamentous fascial and even cutaneous structures in front of the articulation, while the terminal phalanx usually remains more or less helpless. The condition is probably dependent upon an infantile paralysis of the flexors of the affected digit. The use of friction, passive movement, and electricity, may be of value in the early stages.
The description of this curious affection has been left until the last because its true nature is still an unsolved problem, and it is hence difficult to place it in any of the groups already described. It is indeed rather a pathological curiosity than an important item in surgical disease, and many surgeons of long experience have never met with a single example. Of the mechanism of its causation we know almost nothing, of its ultimate tendencies we know little more, and its morbid anatomy is almost entirely speculative. Nevertheless, it has a literature extending over fortyyears, and comprising nearly a hundred separate contributions, the last of which, a model in its way, is a monograph of 250 closely printed large octavo pages, the work of Dr. Carlier.
Trigger finger, thedoigt à ressortof French authors, may be defined as a peculiar defect in the motions of the digit, consisting, first, of an impediment which obstructs the movement of flexion or of extension, or of both, followed, if the motive force be continued, by a sudden cessation of the resistance, and a brusque, spring-like action that often bears a remarkable resemblance to that which accompanies the opening and closure of the blade of a penknife. The first observation was that of Notta in 1850. A finger attacked by this affection generally lies when at rest in a position of flexion, and by a voluntary effort or by passive force may be straightened, with the peculiar result described in the definition, the resistance to extension suddenly yielding with a trigger- or spring-like action; and the same phenomenon is usually but not necessarily repeated when the digit is again bent. In exceptional cases a reverse condition obtains: the passive finger is kept in a state of extension, and it is during flexion that the trigger phenomenon is elicited. The movement may be merely inconvenient, or it may be more or less painful. The sign may be constant, accompanying every movement, or it may be intermittent, disappearing and recurring without any obviousreason. It is usually confined to a single finger, but it may be multiple. The digits most frequently involved are the middle finger, the ring finger, and the thumb, while the index and little fingers are relatively free, and the right side is more often affected than the left. It is rather more common in women than in men (in the proportion of three to two); and much more frequent in adults than in children, but may appear at all ages. The etiology is ill understood. In many cases an important influence, direct or remote, has been assigned to rheumatism; in others the condition has been attributed to injuries of various kinds; in others to occupations necessitating over-use of the digital articulations (as in sempstresses); but no cause has yet been recognised which can account for any large proportion of the examples.
Pathology.—The explanations of the peculiar movement which characterises the disease are for the most part of a purely theoretical character, for, as might be anticipated, the opportunities for direct examination of the structures have been extremely rare. It speaks highly indeed for the ingenuity of our investigators that so many plausible hypotheses have been constructed upon so small a basis of observed fact. The views now open for consideration are as follow: (1) The development of a fringe or other growth in the synovial sheath of the flexor tendons. Such a tumour lying in the synovial cul-de-sac, whichprojects beyond the proximal end of the tendon sheath when the fingers are flexed, would be drawn within the theca during extension of the digit, and might in this way oppose a resistance to the movement which would be overcome as soon as the body had passed the constricted entrance of the theca. (2) A nodose condition of the tendon due to the development of a growth within the tendon or upon its synovial investment. Such a nodosity is said to have been unmistakably palpable in many cases; but in two examples examined by Carlier, where the tactile impression of a node was remarkably strong, the tendons were found perfectly healthy at the point of examination. On the other hand, Leisering of Hamburg actually exposed a nodosity in the profundus tendon at the level of the point at which it entered the canal of the flexor sublimis, excised it, and cured the disease. In another case a fringe-like tumour was discovered springing from the synovial covering of the flexor sublimis. The nodosity accepted as a fact, the “spring” phenomenon accompanying must be explained by the varying resistance of different parts of the theca, the impediment occurring at either of the firm, resistant portions of the canal which lie at the proximal opening of the sheath and opposite the shafts of the first and second phalanges, and the sudden release occurring at the weaker points, just above the metacarpo-phalangeal joint, and infront of the first inter-phalangeal articulation. In the case of the thumb, however, the fibrous sheath is much thinner than in the fingers, and the variations of strength in its different parts are comparatively slight after the inter-sesamoid portion of the canal is passed. An obstruction offered to a nodule in the flexor profundus by the channel in the flexor sublimis has been proposed as a cause; but although this might be accepted for the fingers, it would not apply to the thumb, which has but one tendon within its theca. (3) An alteration in the shape of the articular surface, such as was first pointed out by König in hammer toe. In these cases the movement of the distal bone is intercepted by the presence of a ridge extending transversely across the head of the proximal bone, and when by voluntary or passive force the ligaments are made to yield sufficiently to allow the obstacle to be surmounted, the movement is terminated by a sudden spring-like action of the extensors or flexors, as the case may be. This condition undoubtedly exists in certain cases of hammer toe and hammer finger; but it must be recollected that these two affections are developmental, and always begin during the period of active growth; while the great majority of examples of trigger finger appear in adult life, after the osseous and ligamentous elements of the articulation have assumed their permanent form. Corresponding changes of form, however, mightoccur in rheumatoid arthritis. (4) The development on the side of the head of the proximal bone of an osseous excrescence, so placed that the narrow (proximal) attachment of the lateral ligament must pass over it during the movements of flexion and extension. The possibility of this condition, suggested on theoretical grounds by Poirier, cannot be denied; it is, in fact, normal in the tibio-tarsal joint of the ostrich; but its existence in the human subject has yet to be demonstrated. It might well appear in connection with rheumatoid arthritis, but indications of this disease are found in only a small proportion of cases of trigger finger. (5) Spastic irregularities of muscular action. According to this view, advanced by Carlier, the muscle at fault is nearly always the flexor sublimis. It must be recollected that the flexion of the first phalanx is effected mainly by the interossei and lumbricalis, that of the second principally by the flexor sublimis, and that of the third entirely by the flexor profundus; the extension of the first phalanx is due to the common extensor aided by the special accessory extensors in the case of the index and little fingers; the corresponding movement of the second and third phalanges is accomplished by the interossei and lumbricales. In the thumb the metacarpo-phalangeal joint is acted upon by the long and short flexors in the one direction, and by the extensores primi et secundi internodii in theother, while the distal phalanx is flexed by the long flexor and extended principally by the abductor and flexor brevis, which send expansions to the long flexor tendon. If, then, we assume the existence of a reflex spasm of the flexor of a joint the resistance must be overcome by vigorous action of the extensors, or by passive force; and if under these circumstances the spasm yield suddenly the spring phenomenon might be closely simulated. The theory is ingenious, but it involves certain difficulties in its application to trigger finger in general: first, that the “spring” ought to be confined to the movement of extension, unless we assume—and this perhaps is too much to ask—that a similar spasm may affect the extensor also, and be overcome in an analogous way; secondly, that the spring movement should be greatly altered when the tendon of the sublimis is relaxed by flexion of the wrist and metacarpo-phalangeal joint, a modification that has not yet been recorded; thirdly, that it should disappear during complete muscular relaxation under chloroform, and in some cases at least this has not happened.
For the present we must confess our inability to decide the question. In the majority of cases the tendon nodule hypothesis would explain the phenomenon; and the articular theory might be tenable in adolescent cases or where there is rheumatoid arthritis; but more direct evidence isrequired and closer observation should be directed to the effect of relaxation of groups of muscle by position, and of the muscular system generally by anæsthetics.
The treatment must to some extent share in the uncertainty that attaches to the pathology. The safest and most hopeful measures appear to be a persevering use of passive movement, combined with massage. Surgical operation has been successful in two or three cases, but in others it has missed its mark and has probably left the patient in worse condition than before.